Metathesis with exchange resins

CsAu- dissolves in liquid ammonia to give very pale yellow solutions that are highly conductive as expected for an ionic species. Treatment of an ammonia solution of CsAu with an ion exchange resin loaded with tetramethylammonium ion or metathesis of CsAu with tetramethylammonium chloride in liquid ammonia leads to the formation of the colorless salt (Me4N)Au, whose structure is shown in Figure 3.3. (Me4N)Au , which consists of isolated ions of the two components, is iso-structural with (Me4N)Br. 

After reaction with polymer-supported acids, like Dowex resin, the new Ru complex 9 can be conveniently immobilized by ion exchange. In this novel strategy for the immobilization of Ru-based metathesis catalysts, the amino group plays a twofold role, being first an active anchor for immobilization (vide supra) and second, after protonation, activating the catalysts (electron donating to electron withdrawing activity switch). 

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